The present invention relates to a technique for printing an object to be printed by a black recording agent by using a color recording agent when the remaining amount of the black recording agent decreases in a printer capable of performing a color printing operation.
In an ink jet printer capable of performing a color printing operation, a print control method is known that when black ink is used up during a printing operation, the printing operation is temporarily interrupted, and when the printing operation using composite black obtained by overprinting color inks is permitted, the printing operation is resumed by the composite black (for instance, see JP-A-8-251363).
Here, in order to maintain the printing performance of the ink jet printer, the maintenance of a recording head, for instance, a cleaning operation is preferably carried out. When the recording head is cleaned, the ink is consumed. Accordingly, even when the printing operation is not carried out, a certain amount or more of ink preferably remains in an ink cartridge.
However, the JP-A-8-251363 only discloses that when the black ink is completely used up, the black ink shifts to the composite black.